5.7 Vortec Install Questions - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**truckster** · 03-15-2013, 05:10 PM

I picked up a 97 5.7 Vortec today for my Blazer, and I've got some questions.

How complicated is the wiring and ECM? Would I need to have the ECM flashed, and do I really need to run 4 O2 sensors? What about VSS?

I'm thinking about buying a manifold and putting my Quadrajet and HEI on it to make it simpler.

Any thoughts?

hugger6933 · 03-15-2013, 09:43 PM

It certainly would be the most cost effective route to take to put your carb and HEI on the vortec motor. You will be amazed at the power it will have as well. It will cost a good amount to go with a EFI setup and you will need a tank or a pump to pump the high pressures needed for the engine to run as well as other expensive things that you don't already have. check with some of the LS conversion guys and see what they are spending, it will cost you close to the same money. The lone exceptions will be that the motor mounts will already work and a few of the traditional 350 v-8 things like that

**truckster** · 03-15-2013, 10:21 PM

I ordered a carb manifold for the vortec and I'm going to use my Quadrajet and HEI. Do you know if I need to change the balancer ao I can time it?

I'm looking forward to the extra hp and torque. I hope to get it running next week.

steves1967 · 03-15-2013, 11:17 PM

Are you using the serpentine belt set-up? If not you'll need to change the water pump. Chevy used a reverse rotation water pump on the late 90's Vortec small blocks.

buckskins4ever · 03-15-2013, 11:24 PM

I run 355 Vortec in mine now. I would say go with the HEI distriputor and carb. You are going to have to buy a vortec intake for carb. Plus not only is it a cheaper way to do the swap, you can do a little more hops with the motor that a computer wont allow...(meaning a heavier cam for a good lobe)
As mentioned by another in the post, depending on v-belt or serp setup is going to determine which water pump you will use.

oldschool18 · 03-16-2013, 12:06 AM

Buckskin where did you get the motor brackets for the alt..p/s pump from?

**truckster** · 03-16-2013, 12:27 AM

I was planning on using the serpentine belt and accessories from the Vortec.

Is it going to be possible to time the distributor with the stock balancer?

03-15-2013, 05:10 PM	#1
truckster Senior Member Join Date: Jan 2001 Location: Orem, Utah Posts: 7,977	5.7 Vortec Install Questions I picked up a 97 5.7 Vortec today for my Blazer, and I've got some questions. How complicated is the wiring and ECM? Would I need to have the ECM flashed, and do I really need to run 4 O2 sensors? What about VSS? I'm thinking about buying a manifold and putting my Quadrajet and HEI on it to make it simpler. Any thoughts?

03-15-2013, 09:43 PM	#2
hugger6933 Registered User Join Date: Oct 2008 Location: Marianna Arkansas Posts: 7,280	Re: 5.7 Vortec Install Questions It certainly would be the most cost effective route to take to put your carb and HEI on the vortec motor. You will be amazed at the power it will have as well. It will cost a good amount to go with a EFI setup and you will need a tank or a pump to pump the high pressures needed for the engine to run as well as other expensive things that you don't already have. check with some of the LS conversion guys and see what they are spending, it will cost you close to the same money. The lone exceptions will be that the motor mounts will already work and a few of the traditional 350 v-8 things like that

03-15-2013, 10:21 PM	#3
truckster Senior Member Join Date: Jan 2001 Location: Orem, Utah Posts: 7,977	Re: 5.7 Vortec Install Questions I ordered a carb manifold for the vortec and I'm going to use my Quadrajet and HEI. Do you know if I need to change the balancer ao I can time it? I'm looking forward to the extra hp and torque. I hope to get it running next week.

03-15-2013, 11:17 PM	#4
steves1967 Registered User Join Date: Dec 2001 Location: Manteca, Ca USA Posts: 305	Re: 5.7 Vortec Install Questions Are you using the serpentine belt set-up? If not you'll need to change the water pump. Chevy used a reverse rotation water pump on the late 90's Vortec small blocks. __________________ '71 Chevy 3/4 Ton Longbed '22 Chevy Tahoe RST '67 Firebird- 8 sec street car '24 GMC CC 4x4 Duramax Dually

03-15-2013, 11:24 PM	#5
buckskins4ever Registered User Join Date: Dec 2012 Location: Altoona Iowa Posts: 481	Re: 5.7 Vortec Install Questions I run 355 Vortec in mine now. I would say go with the HEI distriputor and carb. You are going to have to buy a vortec intake for carb. Plus not only is it a cheaper way to do the swap, you can do a little more hops with the motor that a computer wont allow...(meaning a heavier cam for a good lobe) As mentioned by another in the post, depending on v-belt or serp setup is going to determine which water pump you will use. Attached Images

03-16-2013, 12:06 AM	#6
oldschool18 Registered User Join Date: Jan 2010 Location: Hollidaysburg, PA Posts: 785	Re: 5.7 Vortec Install Questions Buckskin where did you get the motor brackets for the alt..p/s pump from? __________________ _________________________________ 62 Impala 70 C-10 LWB 71 K-10 SWB 85 C-10 LWB==SOLD 01 2500 HD Members Met......2003Silverado (Dave)

03-16-2013, 12:27 AM	#7
truckster Senior Member Join Date: Jan 2001 Location: Orem, Utah Posts: 7,977	Re: 5.7 Vortec Install Questions I was planning on using the serpentine belt and accessories from the Vortec. Is it going to be possible to time the distributor with the stock balancer?



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